Improved method of securing tubes in tube-sheets



UNITED STATES PATENT OFFICE.

JOHN H. KNICKERBOCKER, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVED METHOD OF SECURING TUBES IN TUBE-SHEETS.

Specification forming part of Letters Patent No. 35,691, dated June 524,1862.

panying drawings, making a part of this specification, in which- Figure1 is a longitudinal central section of a portion of a boilcniue having.one end secured in the tuhesheet, according to my invention. au, Fig. 2,indicate the plane of section. Fig. 2 is an end View of the same; Fig. 3a longitudinal central section of a line and ferrule, the latter notbeing driven in the former; Fig. 4, the same View as Fig-3 with theferrule driven in the flue.

Similar letters of reference indicate corresponding parts in the severalfigures.

This invention consists in the employment or use of a ferrule having aconcave outer surface of slightly taper form, and of such diameter thatit may be driven into the flue and expand the end of the same in such amanner that it will close snugly around the hole made in the tube-sheetto receive the flue and form a tight and permanent connection of theflue to the tube-sheet, as hereinafter fully shown and described.

To enable those skilled in the art to fully understand and construct myinvention, I will proceed to describe it.

A represents a portion of a tube-shcet of a steam-boiler, and a is acircular hole in the sheet which receives the end of the flue B. Theedge of the hole a is made convex, as shown in Figs. 1, 3, and 4, and itis rather larger in diameter than the flue B, to admit of the latterbeing expanded with it.

C is a fer-rule, the exterior of which is slightly taper from its outeredge to the point a', and is grooved circumferentially, as shown at b,between said points, so as to form a concave surface. The inner part, c,of the ferrule is beveled or tapered quickly from the edge of the grooveb to the end of the ferrule. The external diameter of the ferrule at theinner edge of the groove b, at the point a', is equal in diameter to theinterior of the flue B, as shown clearly in Fig. 3.

The operation of securing the Ilue in the tube-sheet is as follows: Theend of the tine B is inserted in the hole a in the tube-sheet and soadjusted as to extend a trille beyond it. The ferrule G is then insertedin the end of the tlue B, a mandrel, D, placed against its outer edge,as shown in red in Fig. 3, and the ferrule driven in the flue, so thatthe ends ot' the flue and ferrule will be ilush with each other, asshown in Fig. 4. The ferrule C, in being driven into the flue, slightlyexpands its end, and a taper mandrel, E, is then inserted in the ferrulcand driven through it, so as to expand the ferrule and also the endofthe flue until the exterior of the latter is closed tightly all aroundthe edge of the hole a in the tubesheet A and at both sides of it, asshown in Fig. 1. This expanding of the ferrule also causes its interiorto be equal in diameter to the interior of the tlue B, as shown in Fig.1, and colisequently a iu'e of equal diameter internally is obtainedthroughout, and also a smooth unbroken surface with a tight andpermanent connection of the flue and tube-sheet is ob tained.

Taper ferrules have been used with plane exterior surfaces for expandingthe iues and securing them in the tube-sheets; but they have served tocontract the orifices of the fines, and are therefore objectionable onthat account.

I do not claim, therefore, broadly or irre spective of construction aferrule for securing the ues of boilers in tubesheets; but

What I claim as new, and desire to secure by Letters Patent, is

Securing the iues B of boilers in the tubesheets A thereof by means ofthe'ferrules C, grooved at their exterior, tapered, and driven in theends of the tlues, so as to cause the ends of the saine to close aroundboth edges of the holes a in the tube-sheets and admit of the line beingof equal diameter throughout, as herein set forth.

JOHN H. KNICKERBOOKER.

Witnesses:

XV. H. TAsKEE, JNO. D. BLAND.

